How to set a sillimanite?

[glitterata]

I recently bought some cheap and interesting stones, including a 5.4 ct (9 x 11.5 mm) transparent sillimanite. It's a bright greenish yellow that I find very appealing. With perfect cleavage and a hardness of 6.5 - 7.5, I'd better set it as a pendant, not a ring, right? Or would you set it in a ring anyway and just risk it chipping and breaking, given that it cost $25? (Of course, the setting would cost more, even if I go with silver.)

Here it is with an opaque, reddish-black star garnet, which has a very sharp star in direct sunlight and otherwise looks like onyx, and an iolite (cut by Jeff Davies).